1. Field of the Invention
The present invention relates to cantilever shelf structures and, more particularly, is directed to corner shelves suitable for mounting with an adhesive.
2. Description of the Prior Art
The present art discloses various configurations of cantilever shelf structures intended for mounting in a corner.
One popular configuration, which provides attachment at a shelf corner, also allows for vertical adjustment of the shelf. This configuration is exemplified by U.S. Pat. No. 4,132,178 to Mueller et al. which discloses a shelf and corner post combination. The post includes a series of vertically-spaced indentations so as to enable the positioning of the shelf into any of a variety of selected elevations. The shelf is supported at the corner which engages the corner post.
U.S. Pat. No. 4,365,562 to Webb similarly discloses a support assembly for an inside corner formed by a vertical rear wall and a vertical side wall, the walls intersecting each other at a right angle. A single vertical track and a structural member engaging the track provide positioning support for a shelf. Because the loading on the shelf configurations taught by Mueller et al. and by Webb is borne at only one shelf corner, they lend themselves to the support of light to moderate loads.
Another popular configuration utilizes external structural supporting members to provide additional supportive capability. This configuration is exemplified by U.S. Pat. No. 3,906,872 to Erickson which discloses a knock-down corner shelf structure having three rigid interconnected uprights forming a pyramidal structure. Transverse support for the shelf forward portions is provided by shelf support rods which interconnect the two forward uprights.
U.S. Pat. No. 4,244,301 to Nakatsu discloses a corner shelf assembly which also uses external structural supporting members. The external members consist of flexible lines depending from a support hook so as to allow the rearrangement of shelves or the removal of the entire assembly. As can be seen, the two configurations taught by Erickson and by Nakatsu are adapted for the support of more moderate loads by the incorporation of the external structural supporting members.
In applications where a external structural members would be undesirable or obtrusive, a corner shelf assembly such as that disclosed by U.S. Pat. No. 4,727,815 to Miller may be preferable. This configuration uses a bracket to engage one corner of the shelf and allows the abutting surfaces of the shelf to make direct contact with intersecting vertical mounting surfaces. The design is adapted for use in bathroom wall areas and allows for caulking to completely surround the shelf so as to prevent the passage of water through any holes which may have been drilled into the wall tiles.
The prior art does not appear to have provided for a corner shelf configuration, suitable for mounting with an adhesive, which can be used to support moderate to heavy loads without the need for external structural members. As is generally known in the art, the load safely supportable by a non-rigid shelf unit secured by an adhesive is limited because the loading forces tend to distort and flex the shelf and, thus, to urge the shelf abutting surfaces away from the support surfaces. The adhesive layer is placed in tension and may fail. In alternative failure mode, the load is not uniformly distributed along the shelf abutting surfaces. This causes some regions of the adhesive layer to be placed under greater stress, and the highest-stressed regions become the first to experience failure. Consequently, the full shear strength of the entire adhesive layer cannot be utilized.
It is therefore an object of the present invention to provide a shelf structure which does not suffer from the heretofore-mentioned disadvantages and limitations.
It is a further object of the present invention to provide such a shelf structure which is suitable for mounting with an adhesive and, optionally, with mechanical fasteners.
It is a further object of the present invention to provide such a shelf structure which utilizes no external structural supporting members.
It is a further object of the invention to provide such a shelf structure which fully utilizes the properties of a mounting adhesive.
It is a still further object of the invention to provide such a shelving structure which support additional load when attached by nonadhesive means or in conjunction with multiple attachments.
Other objects of the present invention will in part be obvious and will in part appear hereinafter.
The invention accordingly comprises the apparatuses, processes and products, together with their elements and interrelationships, that are exemplified in the following disclosure, the scope of which will be indicated in the appended claims.